Bucket type mechanical mole



May 22, 1962 F. c. PETERSON BUCKET TYPE MECHANICAL MOLE 3 Sheets-SheelI1 Filed sept. 12, 1958 INVENTOR. FRA/VK C. PETERSON BY MI," l 57TH' .J M

A TTORNEV May 22, 1962 F. c. PETERSON BUCKET TYPE MECHANICAL MOLE 3Sheets-Sheet 2 Filed Sept. l2, 1958 1N VENTOR. FRANK C. PETERSON BY MMM,#naal m l WlmdmmllllallhM-hl,flIhllllll!llllllllllllIllllll.lllllll|lllwllllllll` IHIQIM .IF lillmlf... 'I 6 Y \m@ A.. C im n@ n@ Q mm o mm mw A T TOR/V57 May 22, 1962 F.c. PETERSON BUCKET TYPE MECHANICAL MOLE Filed Sept. 12, 1958Sheets-Sheet 5 77 4a 77 54 2e 5gg 23 2 252eE5 24 30 25 26 2a` 25 0 0 40l 4 53 l e4 EIL-* l IVOS INVENTOR. FRANK C. PETERSON ATTORNEY UnitedStates Patent Oice 3,035,821 Patented May 22, 1962 3,635,821 BUCKET TYPEMECHANICAL MOLE Frank C. Peterson, Oroville, Calif., assignor to AmoPlacer Mines, Inc., Oroville, Calif., a corporation of California FiledSept. 12, 1958, Ser. No. 769,804 6 Claims. (Cl. 262-5) This inventionrelates to a digging device, and more particularly to a mechanicaldigging device using the crowd method for underground tunneling anddigging.

Underground `and tunnel vdigging is extremely costly and it is one ofthe purposes of this invention to provide substantially automaticdigging equipment capable of operation -by ya maximum of two men whichwill reduce the digging cost per yard, and accomplish this objectivewithout the necessity of bringing power to the machine, other thanelectricity.

Another object is to provide a mechanical mucking machine which mayreadily be moved into position and continue to be moved forwardly as thedigging progresses by its own means, all without complicated rigging orother supplemental moving equipment.

Still another object is to provide a mechanical digging machine fordigging into the face of a bank, which will dig tight material withoutblasting and its attendant hazards, while, at the same time, willautomatically back o if an unexpected obstacle requiring power todislodge beyond the setting of the automatic drive or thrust controls,is encountered.

Another object is to provide a machine which will dig a cut twenty feetwide and nine feet high from a single base location.

Another object is to provide a mechanical digger which can operatesuccessfully and maintain volume operation in the confines of a six footby six foot tunnel.

A further object is to provide a machine having a continuous bucket linefor accomplishing the digging and delivery of the material to be removedin a relatively steady stream to a conveyor which makes possible the useof continuous belt conveyors, as no large Volume of material is dumpedat any one time.

It is a further object to provide a mechanical digging boom having acontinuous bucket line, using hexagonal drive tumblers for operating thebucket line.

Another object of the invention is to provide a bucket line for suchpurposes with `each bucket having an extended forward lip contiguouswith the back thereof and digging teeth extending outwardly from theheel thereof which loosen the bank for the encounter of the bucketimmediately following.

Still another object of the invention is to provide a digging machinewhich is completely self-contained, not only so far as operating thedigging boom, but with respect to the forward movement of the device,itself.

A further object is to provide such a digging machine made for the mostpart with standard equipment and in which the operating drive unit maybe removed as a unit for overhaul and repair without dismantling theentire machine.

A still further object of the invention is to provide a method ofdigging the face of a bank wherein there is no tendency or opportunityto push the material into the face of the bank and wherein the arc oftravel of the bucket cutting lip is changed during the diggingopertation.

A still further object is to provide automatic controls for the entiredigging and moving operations which can be handled by a single operatorfrom one side of the machine only.

Further objects are to provide a construction of maximum simplicity,economy, and ease of manufacture, also such further objects, advantagesand capabilities as will fully appear and as are inherently possessed bythe device and the invention described herein.

Invention further resides in the combination, construction andarrangement of parts illustrated in the accompanying drawings, and whilethere is shown therein a preferred embodiment thereof, it is to beunderstood that the same is merely illustrative of the invention andthat the invention is capable of modification and change, andcomprehends other details of construction without departing from thespirit thereof or the scope of the appended claims.

Referring to the drawings:

FIGURE l shows the mechanical mole of the present invention in sideelevational View with the digging boom substantially in a horizontalposition. The approximate maximum upward angle of digging and theapproximate lower maximum angle of digging are indicated by the phantombroken lines, as well as the position of the maximum forward digging forany one base location of the machine;

FIGURE 2 is a top plan view of the mechanical digger shown in FIGURE lwith the approximate maximum lateral angularity for the digger shown inbroken phantom lines. The receiving trough at the Irear end has beenomitted in this view; Y

FIGURE 3 is a Arear elevational view of the digger shown in FIGURE l;and

FIGURE 4 is a schematic arrangement, showing the coupled operation ofthe manual hydraulic operating controls for the device.

Referring now more particularly to the drawings in which like referencecharacters have been used to designate like parts in the several views,it will be observed that the mechanical digger of the present inventionis constructed upon a revolving table or tub which is generallyldesignated by the numeral 10. The stationary portion comprises astationary flat plate 11 having a peripheral upstanding flange 12.Immediately above, but out of contact with the top edge of theperipheral flange 12, is base plate 14 which is substantiallycoextensive with the plate 11. The base plate 14 is mountedconcentrically on the stationary plate 11 Yby two cooperating means. Atthe center, a collar 15 secured to the under surface of the base platelits over =a stationary pivot pin 16 which is secured to the stationaryplate 11 at the center thereof. Suitable bearings may be added in thecollar 15 to secure easy rotation of the :base plate 14 around the pivot16 and to take some of the thrust. The other means comprises a pluralityof rollers or heavy casters 17 which are mounted in any suitable manneron the under surface of the base plate 14 for rolling contact with theinner face of theV plate 11. The rollers or casters 17 are mounted onplate 14 in such a manner that the peripheral ange 12 also acts as anouter guide or raceway for the said rollers or casters. For convenienceof forward and rearward drag movement of the tub, a pair of skids 18having suitable coupling openings 20 are provided. The skids 18 rest onthe oor level 21 `and provide clearance for the tub 1t) .as it is movedalong the floor.

It is apparent that the tub 10 can be mounted on any suitable means ofconveyance rather than the skids 18, such as tracks, wheels, rollers ortrack-laying treads. The

use of any of these, however,- may be limited by the space demands ofthe digging.

Mounted in parallel relationship on said base plate in planesperpendicular to the plate 14 and at either side of the longitudinalaxis of the machine are side plates 22 forming a pedestal thereon. Theside plates have a rear overhang portion 23 with parallel longitudinalslots 24. Mounted above and below the opening of each of said slots andon the outside thereof are angle members 25 3 which form slide guides ateither side of the pedestal. The center of the slots 24 lies in thelongitudinal, horizontal plane which represents the'center line 26 ofthe boom assembly, 4which is generally designated 27, when the same isin the horizontal position. Mounted for horizon-v tal sliding actionwithin the groove and slide angle mem' bers 25 at each side are trunnionblocks 28 in which are journaled the horizontal, transverse driven shaft39. As shown in FIGUREI, the shaft 30 also acts as the pivot mountingfor the vertical raising and lowering of the boom assembly 27.

The boom which is generallyrdesignated as 27 is somewhat cigar shaped,closed by vertical sidewalls 31 and by a topY 32. The boom housingenclosesthe driving mechanism which comprises an electricgear motor 33con- Y protected at all times. -It follows, therefore, that eitherv themotor or the transmission may be uncoupled, unbolted and removed-withoutdismantling the remainder of the equipment. The-boom housing andtherefore the entire boom assembly 27 atthe rear end thereof ismounted-for-pivotalmovement about the shaft 30. Suitable thrust bearings38 are provided for this purpose. It is therefore apparent that allvertical movement of the boom assembly 27 has the shaft 30 as its pivotpoint. Mounted on shaft 30 in line with drive sprockets 37 are a pair ofdrivensprockets 40. The sprockets 37 and 4t) at either side areconnected by roller chains 41 which obviously dri-ve simultaneously atthe same rate. Also mounted on shaft St) and driven thereby are a pairof hexagonal tumblers 42. At the beginning of each alternate face oflthe-hexagonal tumbler 42 is a projecting point or tooth 43, the purposeof which will be explained subsequently. Carried at the forward end ofthe boom frame 26 is an idler Shaft 44 suitably journaled at either sideas'atlS.` Mounted-on the idler shaft 44 at either side of the boom is apair of hexagonal tumblers 46 identical with those at' the rear withprojecting teeth at the beginning of each- Extending 'around the hexag-Yonal tumblers 42 and 46 at either side is an endless chain v alternateperimeter face.

47 which' is the bucket chain. The bucket chain Vis composedof alternatesolid and double links having a distance between the connecting linkssuch that in making the turns atieither end the links will t flush alongthe peripheral4 faces of the hexagonal tumblers. The bucket chains aredriven in a counterclockwise direction as viewed in FIG-V URE -1, bymeans of the hexagonal tumblers 42. This is accomplished by the contactof thev projecting points ory teeth 43 engaging in the heels of thesolid 'links with the double-links straddling the projecting points orteeth 43. In this manner and at both ends of the bucket line are alwaysin positive engagement and control of the hexagonal tumblers. Aplurality of buckets 48 is carried bythe chain.

While the buckets 48 have the conventional and usual shape of drag linebuckets, nevertheless there are several important features whichdistinguish Vthis type of bucket line from others previously known. Inthe first place they are secured to the chain at one point only so that4 the digging face on a relatively at curve to ll the bucket. When thebucket is filled and as it passes the longitudinal axis of the boom, thebottom of the bucket swings free of the chain 47 and the digging lip iswithdrawn in a relatively fiat curve in a rearwardlyv direction. Thebuckets are arranged closely together and each bucket has a flat back 51and an elongated forward lip 52 integral therewith. Near the base ofeach bucket on the exterior thereof are a pair of digging teeth 53,which, after the bucket has passed the digging face and been filled,engages the digging face and loosens the material for the next bucket.As the bottom of the filled bucket 48 swings clear of the chain 47 onits delivery passage, the digging teeth 53 engage the digging face withsubstantial power and force to` make the loosening most effective. Indigging very tight material the digging teeth 53 are removed from thebase of the bucket and placed along the digging lip of the bucket.

Since the boom assembly 27 is supported in the frame of the machine onlyby the pivot shaft 30 at the rear, it is apparent that the boom wouldfall-down at the front thereof unless there was some support. At eitherside of the boom housing 31 are laterally extending wings 54 whichextend upwardly at a slight angle. From the outer ends of these wings 54the crowd or lateral support hy` draulic cylinders 56 are suspended by auniversal connecting joint 55. At the other extremity of the hydrauliccylinders 56 extends the piston stem 57 to which is secured a foot 58.The feet 58 are cup-shaped and are hard faced around the edges so thatthey will dig into the floor 21.V The manner of supportingthe boomassembly 27 is clearly shown in FIGURE 3.V Because of the universaljoint 55 and the foot 58, thelateral support orl tion thereof. It isobvious that in so doing the boonr assembly should not be subjected toany twist.

Along the under surface of the boom `at either side and 1n contact withthe travel of the chains 47 aredigging 1 shoes 60 to force the bucketsto dig without contacting the yboom housing. On the top surface at theforward end are carrying shoes 61 to support the loaded bucketsandtokeep them fromengaging the upper surface of the housing.

Also secured to the outer ends-of the forward wings 54 are lateralattaching brackets, the piston stem 63 of the vertical lift cylinders 64are pivotally attachedto the bracket 62 by means of pivot ends 65. Abracket 66, which is firmly secured to the base plate 14, pivotallymounts the lower end of the vertical lift cylinders 64. It will bereadily observed that by raising or lowering the piston rods 63, theboom lassembly 27 may be raised or lowered to any adjusted positionwithin the limits of the device. Because 0f the forces applied to theouter ends of the wings 54 it has been deemed advisable to provide a tiebrace 67 connecting the two extremities. Obviously the tie brace 67 isarched so there will be no interference with the `buckets passingbeneath it.

It has been found advisable, particularly with respect to the forwardhexagonal tumblers 46, to cover them with removable protective circularcovers 68, which, of course, do not interfere in any way with theoperation of the boom or the buckets and do not move.

Fitted longitudinally between the slides at each end of the side plates22 and secured to the side plates is a pair of hydraulic cylinders 70,one at either side. stem V71 for these cylindersis secured toV the block28. It is apparent that since the shaft 30 is movable longitudinally inthe slots 24 and slide guides 25 by means of its mounting blocks 28, theentire boom may be moved forwardly and rearwardly within the limits ofthe stroke of the piston 71. Thus, the boom assembly 27 can be movedAforwardly without 'moving the entire machine itself and can dig asubstantial amount without being,

The pistonstopped for movement of the entire machine to another forwardposition. Although the pressure in cylinders 70 is the same as thatapplied to any other cylinder in the system, nevertheless it is set andcontrolled at a lesser pressure -by the setting of the relief valvemechanism 72. Thus, the machine can only dig up to the predeterminedpressure setting of the cylinder and no more. Accordingly, in thedigging operation, if the bucket line encounters an object requiring aforce greater than the drive or thrust of the setting, the boom willautomatically back olf due to release of iluid pressure in the cylinders70 and when this object is passed, the pressure is restored to thecylinders and the boom moves forward again. In this manner the diggingforce of the boom and twin bucket line is not jeopardized and damage tothe machine is minimized.

Mounted at either side on the side plates 22 forming the pedestal areupwardly directed hydraulic cylinders 73 with their piston stems 74pivotally connected to an overhead cross brace 75. At the centralportion of the cross brace 75 is a pad '76 for bearing against theceiling of a tunnel. The pad 76 may be rotatably mounted to provide forrotation of the machine without releasing the bearing pressure on theceiling. In order to secure better anchoring of the machine to theceiling of the tunnel and thereby promote better digging performance,are a pair of bar members 77 angularly disposed and pivoted at one endto the cross brace 75 and at the other end to the upper overhang portionof the side plates 23. The support of the bar members '77 minimize thelikelihood of bending the stems 74.

At the rear or discharge end of the chain bucket line is a receivingtrough 7S which has inwardly sloping sides 80, the bottom of the troughbeing an endless belt conveyor 31 driven by a separate motor 82. Themotor 52 and 'the drive pulle S3 for the belt conveyor 31, as well asthe receiving trough 7S, are mounted between the side plates 22 on thebase plate ill-i for rotative movement therewith. To maintain thisposition land for reinforcement accommodating the weight of the materialdelivered to the belt conveyor 3l, rigid side brackets 84 are secured tothe receiving trough 73 at either side and are anchored at the topthereof to the lower portion of the side plate overhangs 23 of thepedestal. The delivery end of the receiving trough 78 must necessarilyalways be in position with respect to the receiving end of the normalbelt conveyor S5. For this purpose `a pivotal coupling has been devisedwhich will maintain this relative position regardless of the diggingposition of the machine. Since the delivery end of the belt conveyor inthe trough 78 must overlay the receiving belt 86 of the normal conveyorS5, a bracket 87`is secured to the under portion of the receiving trough7S. To this bracket 37 is secured an outwardly projecting face plate 88having an aperture therethrough. To the under support 90 for the normalbelt conveyor 85 is secured a pivot pin 91 which projects through a faceplate 92 also secured to said bracket 90. rIhe pivot pin 9i projectsthrough the aperture of the face plate d8, bringing the two face plates92 and $8 into contact with a substantial supporting surface in contactand providing a pivotal mounting. In this manner the delivery end of thereceiving con eyor 7 S is always maintained in appropriate position withthe normal conveyor 85.

Referring now to FGURE 4 and particularly to the diagrammatic showingtherein, a typical flow control diagram is shown for the operation ofthe hydraulic cylinders in the operation of valve lil-fl. However,FlGURE 4 has speciiic reference to the necessary simultaneous opera-tionof valves 104iand 105. In order to allocate or orient `the controls forthe machine, it is to be noted that the controls are all on the rightside of the machine so that a single operator manipulating the controlvalves can control all of the movements of rthe device. The hydrauliccontrols are valves generally designated 100.

Referring to FIGURE 1, valve 101 controls the simultaneous operation ofcylinders 70 and moves the boom assembly 27 forwardly and rearwardly.Valve 102 controls the simultaneous operation of cylinders 64 forraising and lowering the boom assembly. Valve 103 controls thesimultaneous operation of the cylinders 73 for anchoring the machineagainst the ceiling. Valves 104 and 105 must be operated conjointly andcontrol the mov-ement of .the anchoring cylinders 56. Each of thecontrol valves is a dual acting valve which has a central neutralposition and is moved away from the operator for one direction andtoward the operator for the reverse direction. Valves i101, 102 and 103may be operated independently, but valves 104 and 105 must be operatedin conjunction with each other and can be moved forward together orrearwardly together or in opposite directions together. This llexibilityis of course required because of the varying conditions which arefrequently encountered in positioning the anchoring feet 58. This meansthat either cylinder may be reversed, ie., the piston in one cylindercan be pushing downwardly while the other is being released and movedupwardly, or both can go in t-he same direction at the same time oreither can be stationary while the other moves. To obtain this actionthe valves 104 and 105 are arranged in parallel with a double ball checkvalve 106 between them. As diagrammatically shown in FIGURE 5, when thevalves are in the neutral position, liquid in the feed line 1437 passesthrough Valve 104 and out to the discharge line to the reservoir 108.If, for example, the valve 1041 is opened to put pressure in thecylinder 56 and extend the piston stem 57, Athe incoming liquid in line1457 would be fed to the line 110 to the pressure side of the cylinder56. At the same time liquid would be delivered to the double ball checkvalve 106 and liquid would flow into the valve 105. If the valve were inythe neutral position the liquid would ow through the valve into thedischarge line 108 `to the reservoir. However, if both valves wereopened simultaneously to the pressure side of their respective cylinders56, then liquid would be delivered to line ll to the pressure side ofits cylinder 56. Of course the opposite is true. If valve le@ is movedto reverse the direction or rearwardly, then fluid pressure is deliveredto the line 1-11 and at the same time to the opposite side of the doubleball check valve 106, to the valve 105. If the valve in i105 is moved inthe same direction, -then lluid is delivered to the line 111. Sincefluid pressure is fed to valve 105 through valve 10d, to operate valve105 alone it is necessary to hold valve 104i in a pinched position ineither direction. This means that valve 104 is opened sumciently topermit fluid to pass therethrough to valve 105, but not sucient -tooperate cylinder 56 through lines 1li) or 111. This maneuver is neededin retracting the foot 58, and is used only at a time when there is nolo-ad on the foot.

In this manner a single operator controls the entire digging operationand movement of the machine. However, he does require a helper on theopposite' side to assist with the placing and anchoring of the Afoot 53and cylinder 55 on that side and to appraise him of the extent of themovement permissable for the boom on the opposite side to him.

In order to prevent any canting in the raising and lowering of the boomassembly 27 and to assist in minimizing any canting or twist during thedigging operation, the side plates of the boom 31, just ahead of theaxis of rotation of the base, are provided with rollers which roll`against the inner faces of the side plates 22 forming the pedestal of`the machine. These rollers not only provide a smooth vertical movement,but prevent the likelihood of twisting or canting of the boom in thepedestal, resulting in twisting and Abinding of the shaft 30.

It is to be understood that the device carries its own liquid reservoirand pressure system, including a motor and pump for handling the lluidpressure systems. Since this is all conventional equipmentitis notshown. However, these are preferably located on theV side opposite tothe controls as there is more room for the mounting and more protectionfor the equip-ment.

Also mounted on and secured to the base plate 14 are upstanding circularskirts 9S. These skirts 95 serve as protection for the operator at oneside and for the helper at e opposite side of the machine against anyinadvertence in contacting any part of the machine. The skirts do notextend forwardly or rearwardly enough to interfere with the movement ofthe boom assembly 27, nor high enough to prevent easy opera-tion of thecontrol valve-s tilll.

Operation The operation of the device is really quite simple. Thedigging machine is moved up to the digging face with the boom assemblyin substantially horizontal position and with the boom itself in themost rearwardly position accomplished by cylinders 7i). lf it is atunnel operation, then the machine would be approximately in the middleof the center of the tunnel floor so as to take advantage of the maximumlater-al movement of the boom. Having thus positioned the machine theoperator then pulls valve 103 toward him, raising the overhead crossbrace 75 until the pad 76 is firmly positioned against the ceiling ofthe tunnel. In this manner there is a downward pressure on the base ofthe machine. At the same time, :by means of Iangular bar members 77 therear overhang portion Z3 of the side plates 22 forming the pedestal onthe base are firmly positioned and steadied. These kbar members 7'7 alsofunction to prevent any bending of the piston stems 74. When the properholding position or the ceiling brace and pad 76 is assumed the valve@d3 is moved to neutral position, maintaining the fluid pressure toaccomplish the holding. Next valve 102 is pushed away yfrom the operatorto remove liquid from the cylinders 64 so that the stems 63 areretracted within the cylinders, lowering the boom assembly to itslowerrnost digging position which is substantially that shown in FIGURE1 as position L. lt is apparent that the lowermost posit-ion will dig tothe iioor level 2i and that the position L of the drawings is not quitethe maximum position. The valve 102 is then moved to the neutralposition so that the boom is maintained in this position. Valves 1434and 165 are then operated and manipulated to iirst extend the stems 57until one of them reaches the door level. For the purpose of thisdiscussion we will assume, for example, that the stem on the side of thehelper is moved so that the foot 5S engages the iloor 21. Accordingly,by continuing the extension of this stem, the entire base plate pedestaland boom assembly are rotated on the pivot 16 laterally to the positionM shown in FIGURE 2. The pad 76 of the ceiling anchor is axiallylaligned with the pin 16 and is so arranged as to permit this rotationwithout release of the pressure. The machine is then ready for thedigging operation and the starter switch is pressed to operate the motor33, driving the transmission 34V and operating the twin chain bucketline comprising chains 47 and the buckets 4S. As viewed from theoperators side shown in FIGURE l, the chain bucket line travelscounterclockwise so that the front edge of the buckets approach thebank, cut into the same, load, and then transport the removed materialrearwardly where it is dumped into the receiving trough 78 4and fromthence onto the standard conveyor belt S5. It will be observed that asthe empty buckets 48 approach the digging end, the chain moves upwardlyat a slight angle with the chain being held taut by the digging shoes60. As the chain is picked up by Vthe hexagonal tumblers 46, the bucketbeing attached to 4the chain only at a single point Si) will travelupwardly and outwardly to the maximum point where the meeting cornerofthe hexagon beneath the front edge of the cup is on the longitudinalcenter line of the boom. From this point on, the bucket lip is withdrawnand the'arc of the lip proceeds in a gradually reducing diameter untilit Vleaves the influence' ofthe hexagonal tumblers 46. Accordingly,

by using the hexagonal tumblers which change the arc` of the travel ofthe bucket line -at each end, the -arc of the bucket digging lip alsochanges so that after it passes the center line the bucket pulls awayfrom the bank to shear the material rather than pull upwardly againstthe ceiling. lit thus follows that the bucket in digging travels in awider arc until a point is reached which corresponds with the filling ofeach bucket, after which the iilled bucket moves from the digging facein a substantially reduced and different arc caused bythe falling ofeach bucket back upon its flat back Si after passing the longitudinalcenter lineV of the boom, as shown in FIGURE l. if ordinary sprocketswere used, the digging motion would tend to push the rock into the bankor the face which, of course, cannot be done successfully. The changingof the arc accomplished by the present device is a great advantage,particularly in the digging of tight material. As before described,also, the heel of the buckets 4S carry a -pair of digging teeth 53 whichcome into operation against the cutting face after the bucket has passedover and above the horizontal center line of the boom. ri`hese teeth diginto the face of the bank, loosening the material in preparation for thecutting and loading of the following bucket.

As has been before described, the back of each bucket hasintegralforwardly extended lip 52 which reaches almost up to the bucketimmediately ahead. This extended lip performs two important functions,one is it acts as a spill carrier for the rearward transportation of theloaded buckets. As can be seen in FlGURE l, the loaded bucket is turnedon its back and carried rearwardly, spilling some of the contents ontothe lip 52 which otherwise would be spilled onto the top of the boom,unnecessarily loading the same and fouling the twin chains. The otherfunction of the lip occurs at the discharge end. Here the lip is longenough to provide a chute and prevent spilling of the contents of thebucket until the lower bucket is completely out o-f the way. As themachine is operated and digs into the face of the bank, the operatorgradually moves the boom assembly upwardly in a vertical arc byoperating valve itil and moving it outwardly. The boom is movedgradually in a vertical arc until it reaches its maximum digging heightwhich is substantially the position shown in FIGURE l as N. |The boom isthen rotated on its base to the next position'where the same procedureis repeated Vand this occurs in increments along the digging face untilVthe digging has been completed to the maximum distance to the left-handside or the position shown as P in FIGURE 2. Then the same proceduresare repeated by operating the valve lill to move the boom forward byincrements until the maximum forward distance D indicated by the brokenline position Q in FIGURE 1 has been attained. Since the maximum diggingfor the original face position Vhas been accomplished by all of thesemaneuvers of digging from position L to position N in all of thehorizontal increments from M to P and all the vertical increments `fromthe minimum setting of the boom to the maximum reach Q, it is nownecessary to move the entire base 10 forward, which moves the positionof the entire machine, and repeat the same procedures.

The device illustrated in FIGURE l can be moved forwardly under its ownpower by releasing the ceiling stabilizer contact and withdrawing thestems 74 of the cylinders 73, releasing the anchorage of the cylinders56 and swinging these into a rearward position andy using them aswalking cylinders. By doing this several times the de'- vice may beadvanced forwardly the required distance to the proper operating contactwith the face of the bank.

Obviously, if space permits, the base l0- may be mounted on wheels orrollers with or without tracks or on a track laying tractor land movedagain under its own power. These, however, are only obvious ways ofaccomplishing the nondigging, forward movement of the entire machine andare only possible where space permits.

It is to be understood that as the various digging procedures arefollowed, the receiving chute 7S attached 'at the rear end of thepedestal and movable therewith, follows 4the horizontal rotatingposition, but swings oppositely to that of the digging end of the boom.Since the loading end of the conveyor belt 85 is supported by thebracket 87 and lip 88, this end swings to accommodate the position ofthe receiving conveyor 7S so that they are always in line. It is notnecessary to uncouple the pivot 99 as the boom moves from retractedposition to its extended position Q, `because the lbracket 37 is mountedin a slot or guide in the bottom of the receiving conveyor 7S.

l claim:

l. A mechanical mole of the type described comprising in combination abase, a horizontally pivoting pedestal on said base, a boom mounted atone end for slideable movement in a horizontal plane on said pedestalrearwardly of the vertical axis thereof for movement therewith in ahorizontal plane and pivotally mounted in said sliding mounting lforseparate movement in a vertical arc, a continuous chain and bucket linetraveling on the upper and lower faces of said boom, said buckets beinghingedly mounted on said chain each adjacent the lip thereof, to swingaway from the chain in other than a circular path at each end of theboom, said lbuckets having a forwardly extending elongated at lipintegral with the back thereof and digging means externally mountedadjacent the trailing edge for loosening the digging face for the nextsucceeding bucket, hexagonal tumblers mounted at each end of said boomfor driving said chain and bucket line and cooperating with said bucketmounting vfor varying the arc of the bucket travel at the turns, saidtumblers having beginning triangular points projecting from alternateperipheral Ifaces for engaging the pivot pins between the double linksof said chain, hydraulic means mounted on said base at either side ofsaid boom to adjustably raise or lower said boom in a vertical arc andhold the same in the adjusted position, power means mounted within saidboom and connected to at least one of said tumblers for driving saidchain and bucket line and control means for separately moving the boomand bucket line forwardly in said slideable mounting to keep the bucketsin contact with the digging face, within the limits of the slideablemounting.

2. A mechanical mole for underground digging comprising in combination abase, hydraulic means supported on the base for adjustably `andpivotally anchoring the machine to the ceiling, a horizontally pivotingpedestal on said base, `a boom mounted at one end for slideable movementin a horizontal plane on said pedestal rearwardly of the vertical axisthereof for movement therewith in a horizontal plane and pivotallymounted at its rear portion in said sliding mounting for separatemovement in a vertical arc, a continuous twin chain bucket linetraveling on the upper and lower faces o'f said boom, said buckets beinghingedly mounted on said chain each adjacent the lip thereof, to swingaway from the chain in other than a circular path at each end of theboom, said buckets having a forwardly extending elongated flat lipintegral with the back thereof and digging means externally mountedadjacent the trailing edge yfor loosening the digging face :for the nextsucceeding bucket, hexagonal tumblers mounted at each end of said boomfor driving said chain bucket line and cooperating with said bucketmounting for varying the arc o'f the bucket travel at the turn, saidtumblers having beginning triangular points projecting from lalternateperipheral faces for engaging the pivot pins between the dou-ble linksof said chains, hydraulic means mounted on said base at either side ofsaid boom to simultaneously adjustably raise or lower said boom andchain bucket line in a vertical arc and hold the same in the adjustedposition, hydraulic means for rotating said pedestal to move said boomand chain bucket line horizontally in the adjusted position, and powermeans mounted within said boom and connected to one of said tumblers fordriving said chain bucket line, and means for separately moving the boomand bucket line forwardly from the adjusted position in the slideablemounting to keep the buckets in contact with the digging face, withinthe limits of the slideable mounting.

3. A mechanical mole of the type described comprising in combination abase, a horizontally pivoting pedestal on said base, a boom mounted atone end for slideable movement in a horizontal plane on said pedestalrearwardly of the vertical axis thereof for movement therewith in ahorizontal plane and pivotally mounted at its rearward portion inslidea-ble mounting for separate movement in a vertical arc, acontinuous twin roller chain bucket line traveling over the upper andlower faces of said boom, said buckets being hingedly mounted on saidchain each adjacent the lip thereof, hexagonal tumblers mounted at eachend of said boom for driving said chain bucket line and cooperating withsaid bucket mounting for varying the arc of the bucket travel at theturn, said tumblers having beginning triangular points projecting fromalternate peripheral `faces for engaging the pivot pins between thedouble links of said chain, hydraulic means mounted on said base ateither side of said boom to simultaneously adjustably raise or lowersaid boom and chain bucket line in a vertical arc and hold the same inthe adjusted position, hydraulic ram means spaced from either side ofsaid boom secured thereto in the plane forward of the center line ofhorizontal rotation for rotating said pedestal boom and chain bucketline horizontally and anchoring the same in the adjusted position eithervertically, laterally, or any combination thereof, power means mountedwithin said boom and connected to `one of said tumblers for driving saidchain bucket line, and means for separately moving the boomand bucketline forwardly from the adjusted position in the slideable mounting tokeep the buckets in contact with the digging face, within the limits ofthe slideable mounting.

4. A mechanical mole for underground digging which can be self-propelledto the digging face, comprising in combination a base, hydraulic meanssupported on said base and movable therewith for -adjustably andpivotally anchoring the machine to the ceiling, a pedestal mounted onsaid base `for pivotal movement in a horizontal plane the axis of whichis in line with said ceiling anchoring, va. boom mounted at one end forslideable movement in a horizontal plane on said pedestal rearwardly ofsaid axis -for horizontal rotation therewith and pivotally mounted atthe rearward portion in said slideable mounting for independent movementin ya vertical arc, a continuous twin roller chain ibucket linetraveling along the upper and lower faces of said boom, said bucketsbeing hingedly mounted on said chain each adjacent the lip thereof,hexagonal tumblers mounted at each end of said boom for driving saidchain bucket line and cooperating with said bucket mounting for varyingthe arc of the buckets travel at the turns, said tumblers havingbeginning points projecting from alternate peripheral faces `forengaging the pins between the double links of said chain, hydraulicmeans mounted on said base at either side acting simultaneously forraising and lowering the said boom on its pivotal mounting n a verticalarc, hydraulic ram means spaced from either side of said boom securedthereto vforwardly of the axis of rotation of said pedestal forhorizontal movement of said pedestal boom and chain bucket line and foranchoring the same in the adjusted position either vertically,laterally, or any combination thereof, power means mounted within theboom and connected to one of said tumblers for driving said chain andbucket line, and means for separately moving thetboom -and bucket linevforwardly from-the` adjustedrposition in theslideablemounting to keepthe buckets'in' contact -with the digging face `rwhilerin the `adjustedposi-V zontal plane the vertical axis of which is in line with said'Vceiling anchoring,-a boom mounted atthe rear `end thereof for slideablemovement in a hor-izontalplane on said pedestal rearwardly of s-aid axisyfor horizontal rotation therewith and pivotally mounted at the rear endthereofin said slideable mounting` for'independent movement in averticalv arc, a continuous twin rollerchain bucket line traveling alongthe upper and Alower'faces of said boom, said buckets being hingedlymounted on said chain each adjacent the lip thereof, hexagonal'tumblers`mounted at each end of said boom for driving said chain bucket lineandcooperating with saidl bucket'mounting for varying the arc 'of thebucket travel at the turns, said tumblers having beginnnig pointsprojecting from alternate peripheralffaces for engaging the pins betweenthe' doublek links of said chains, hydraulic means vnounted onA said?base at either'side acting simultaneously for raising and loweringthe'boomv and chain bucket lin'e in a vertical arc on' its pivotalmounting, hydraulic means for vlimited hor'i` zontal Y forward andrearward -f movement of--said boomi and rchain'bucket line insaid`slideable mounting independently'of said pedestal; hydraulicy ra'mmeans spaced from either sidev ofsaid boom secured thereto forward ofthe axis'of rotation of said base for rotating th'eped'-A estal, boomand chain bucket line laterally `and anchoringA thesame in the adjustedposition either vertically,`ilateral1y, or any combination thereof,valvesystems vfor controlling,

adjusting and holding the setting of thevariou's hydraulic means eachindependently Vof the other, yand power means mounted within theboom'and connected to one of said tumblers for driving saidchainbuck'etline.

6. A mechanical mole lfor underground digging 'com-V prising incombination azself-propelled base, hydraulic means'supported on saidfbase'for adjustably and pivotally anchoring the machine to the Vceilingwhen in position, a pedestal mounted on said base Afor pivotal movementin a horizontal plane the vertical axis of which is in line with saidceiling anchoring-a boomV mounted at the. rear end thereof for slideablemovement in a horizontal plane on said pedestal rearwardly of said axisfor horizontal` rotation therewith and pivotallymounted at the rear endthereof in said slideable mounting for independent movement in avertical arc, a continuous tW-inroller chain bucket line travelinglalong the upper and lower faces of said boom, said buckets beinghingedly mounted on said chain each `adjacent the lip thereof, hexagonaltumblers mounted at each end `of said boom for driving said chain bucketline and cooperating wtih said bucket mounting for varying the arc .ofthe bucket travel at the turn, said tumblers having beginning pointsprojecting from alternate peripheral lfaces for engaging the pinsbetween the double links of said chains, hydraulic means mounted on saidbase at either side lacting simultaneously for raising andV lowering thesaid boom and chain bucket line in a Vertical arc on its pivotalmounting, hydraulic means for limited horizontal forward and rearwardmovement of said boom and chain bucket line independently of saidpedestal, hydraulic ramrmeans spaced fromeither side combinationthereof, a plurality of valve systems for controlling, adjusting andholding the setting of the various hydraulic means each independently ofthe other, and power means mounted within the boom andconnected to oneof said tumblers for driving said chain and bucket line.

References Cited in the file of this patent UNITED STATES PATENTS 60,774Molyneux Ian. 1, 1867 452,492 Whitcomb May 19, 1891 824,531 DucellierJune 26, 1906 878,460 Greer et al. Feb. 4, 1908 884,960 Suiter Apr. 14,1908I 1,246,527 Bentson Nov. 13, 1917 1,561,105 Otto Nov.` 10, 19251,579,704 Grow Apr. 6,1926' 1,850,364 Vaughn Mar.V 22, 1932v 1,987,982Wheeler Jan. 15, 1935 2,290,325 Hammond July 21, 1942 2,311,834 Hollmannet al Feb. 23, 1943 2,363,682 Madsen et al Nov. 28, 1944 2,528,748Greene Nov. 7, 1950 2,597,036 Roe May 20, 1952

